TY - JOUR
T1 - Enhancement of low-temperature thermometry by strong coupling
JF - PHYSICAL REVIEW A
Y1 - 2017
A1 - Correa, Luis A.
A1 - Perarnau-Llobet, Marti
A1 - Hovhannisyan, Karen V.
A1 - Hernandez-Santana, Senaida
A1 - Mehboudi, Mohammad
A1 - Sanpera, Anna
AB - We consider the problem of estimating the temperature T of a very cold equilibrium sample. The temperature estimates are drawn from measurements performed on a quantum Brownian probe strongly coupled to it. We model this scenario by resorting to the canonical Caldeira-Leggett Hamiltonian and find analytically the exact stationary state of the probe for arbitrary coupling strength. In general, the probe does not reach thermal equilibrium with the sample, due to their nonperturbative interaction. We argue that this is advantageous for low-temperature thermometry, as we show in our model that (i) the thermometric precision at low T can be significantly enhanced by strengthening the probe-sampling coupling, (ii) the variance of a suitable quadrature of our Brownian thermometer can yield temperature estimates with nearly minimal statistical uncertainty, and (iii) the spectral density of the probe-sample coupling may be engineered to further improve thermometric performance. These observations may find applications in practical nanoscale thermometry at low temperatures-a regime which is particularly relevant to quantum technologies.
VL - 96
ER -
TY - JOUR
T1 - Achieving sub-shot-noise sensing at finite temperatures
JF - Physical Review A
Y1 - 2016
A1 - Mehboudi, Mohammad
A1 - Correa, Luis A.
A1 - Sanpera, Anna
VL - 94
IS - 4
JO - Phys. Rev. A
ER -
TY - JOUR
T1 - Individual Quantum Probes for Optimal Thermometry
JF - Physical Review Letters
Y1 - 2015
A1 - Correa, Luis A.
A1 - Mehboudi, Mohammad
A1 - Adesso, Gerardo
A1 - Sanpera, Anna
VL - 114
IS - 22
JO - Phys. Rev. Lett.
ER -